Re: Taking the sting out of lumbar puncture
The Pencil Point Would be Progress
Rizzoli suggests that use of ‘cleaner, less traumatic taps’ (pencil-point needles) when performing lumbar puncture may paradoxically increase the risk of headache following the procedure. This is, by his admission based on unconfirmed clinical impressions. Research into this area has been on going for decades and what Rizzoli suggests is not supported by either the American Society of Anaesthetists (ASA) or by the American Academy of Neurologists (AAN).
In anaesthetic practice it is accepted that pencil point-needles (atraumatic) have a lower incidence of post dural puncture headache (PDPH) than cutting needles. This was demonstrated for the first time over 60 years ago. The rate of PDPH can be reduced by a factor of 18 simply by using pencil-point needles in the place of cutting needles from 36% to less than 2%. The evidence seems irrefutable. The American Society of Anaesthetists and the American Academy of Neurologists advocate replacing cutting needles with the pencil-point type. The leak of cerebral spinal fluid (CSF) from the subarachnoid space may lead to other complications including hearing loss(1). In severe cases, the loss of CSF leads to low intracranial pressure and tearing of the subdural vessels resulting in subdural haematoma which may require neurosurgical intervention (2).
Anecdotal evidence of possible reduction in headache incidence by causing an increase in clotting factors in the area of the tap may be possible. In anaesthetic practice this is an epidural blood patch and used in the treatment of post dural puncture headache. Blood in the epidural space may result in an epidural haematoma, which carries its own morbidity and mortality. Although ultrasound may help increase the success rate of these procedures, pencil point needles do reduce the complications and do not require any further education or adaption of technique.
1. Arendt K, Demaerschalk B, Wingerchuk D, Camann W. Atraumatic Lumbar Puncture Needles. The Neurologist 2009;15:17-20
2. Davies J, Murphy A, Smith M, O’Sullivan G. Subdural Haematoma After Dural Puncture Headache Treated By Epidural Blood Patch. Br J Anaesth 2001;86:720-723
Competing interests: No competing interests